9978999 has 8 divisors (see below), whose sum is σ = 13556592. Its totient is φ = 6527040.

The previous prime is 9978989. The next prime is 9979019. The reversal of 9978999 is 9998799.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 9978999 - 2¹⁷ = 9847927 is a prime.

9978999 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9978919) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 31222 + ... + 31539.

It is an arithmetic number, because the mean of its divisors is an integer number (1694574).

Almost surely, 2^9978999 is an apocalyptic number.

9978999 is a deficient number, since it is larger than the sum of its proper divisors (3577593).

9978999 is a wasteful number, since it uses less digits than its factorization.

9978999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62817.

The product of its digits is 3306744, while the sum is 60.

The square root of 9978999 is about 3158.9553653067. The cubic root of 9978999 is about 215.2925456927.

The spelling of 9978999 in words is "nine million, nine hundred seventy-eight thousand, nine hundred ninety-nine".